将 image, audio和 video 保存至sd card

File f = null;

            try {
                f = setUpPhotoFile(); //setUpPhotoFile() 产生一个文件
                mCurrentPhotoPath = f.getAbsolutePath();
                takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(f));
            } catch (IOException e) {
                e.printStackTrace();
                f = null;

            }